Interfering bids. Sacrificing
How to stop them from getting way ahead - Sacrifice
Going down 2 ? Could be better than the enemy making a score.
As beginners, we instinctively don't like to bid a contract we can't make. We don't like the shame and embarrassment of apparent failure.
But then you might notice that the real winners at the end of the evening have, quite often, apparently failed to make various contracts by a small margin, typically costing them 100 points or so. What's more, from their cards, the losing outcome was rather predictable. However, on further investigation, it often turns out that other players of the same cards had suffered a loss of 400 to 600 on the score card, by letting their opponents making a game contract out of their rather good cards.
A well worthwhile sacrifice. And no embarrassment.
Another reason to make a sacrificial bid is to entice the enemy into bidding to just one level beyond what is achievable. This is often the best outcome. For example, let's say the enemy can see that a game bid in hearts is almost on the cards, given their combined 22/23 High Card Points and 8-card fit. Of course they fancy the 140 points in prize money, and so naturally they bid a 3
contract, and then stop. To their annoyance, you then bid 3
. They know you are likely to go down a trick, maybe 2, but probably no more than that, because of your long Spades and shortage in Hearts. Your bid leaves the enemy with three choices
- doing nothing (and winning 50-100 in penalty points)
- doubling (and perhaps making 100 to 300 assuming you are not vulnerable - as well as risking a 480 penalty if you make your contract), or
- pushing it one higher (if they are vulnerable, this would be worth 620 to them)
So they bid again at 4. And guess what? They will often go down, and their calculations of making either 100-300 or 620 turn into a loss of 100.
Defend or play? PUN!
Play: Unbalanced, Non-vulnerable
With an unbalanced hand, it's usually better to play than to defend. After RHO opens 1NT, what would you bid with this hand ?
J1098765 75 
AK 
87
Passing to defend seems like a possibilty (it didn't work), but with 7 trumps you'll probably be better off in 2 Spades. You've got 6 tricks guaranteed, so if partner has nothing at all, you'll only go down 2.
Neither side vulnerable is a great position to play, rather than defend.